Marc A. Pfeffer

Bio: Marc A. Pfeffer is an academic researcher from Brigham and Women's Hospital. The author has contributed to research in topics: Heart failure & Myocardial infarction. The author has an hindex of 166, co-authored 765 publications receiving 133043 citations. Previous affiliations of Marc A. Pfeffer include Partners HealthCare & University of Miami.

Mortality following a cardiovascular or renal event in patients with type 2 diabetes in the ALTITUDE trial

Abstract: Aims Patients with type 2 diabetes mellitus (T2DM) are at high risk of developing cardiovascular (CV) and renal disease. We examined the burden of, and risk of death following, CV and renal events in the Aliskiren Trial in Type 2 Diabetes Using Cardio-Renal Endpoints (ALTITUDE), a randomized trial of alikiren vs. placebo. Methods and results We followed 8561 patients with T2DM and evidence of chronic kidney disease, CV disease, or both in ALTITUDE until the first non-fatal CV or renal event of myocardial infarction (MI), stroke, heart failure (HF), and end-stage renal disease (ESRD; initiation of dialysis, renal transplantation, or a serum creatinine concentration above 6.0 mg/dL) and then to death or censoring. Time-updated multivariable Cox models were used to estimate the relative risk of death following each event. In total 1008 patients (12%) experienced at least one first non-fatal CV or renal event (4.1% HF, 2.8% MI, 2.8% stroke, and 2.2% ESRD). Death occurred subsequently in 26.4% of those experiencing a first HF event, 29.7% of those experiencing an MI event, 23.7% of those experiencing a stroke, and 14.7% of those experiencing ESRD, and in 6.5% (488) of the 7553 patients (88%) who did not experience a non-fatal CV or renal event. Compared with patients who did not experience a non-fatal event, the adjusted hazard ratio for death was 5.9 (95% confidence interval 4.6–7.6) after HF, 9.7 (7.5–12.6) after MI, 7.1 (5.3–9.5) after stroke, and 5.8 (3.7–9.0) after ESRD. Conclusion The majority of deaths occurred in patients who did not experience a non-fatal CV or renal event, although the risk of death was higher following an event. Our findings illustrate continuing opportunities to reduce morbidity and mortality in patients with type 2 diabetes.

Endothelin-A receptor antagonism during acute myocardial infarction in rats.

Abstract: Endothelin levels are increased in rats with experimentally induced myocardial infarction. The purpose of this study was to determine whether endothelin-A (ETA) receptor antagonism alters ventricular remodeling and the development of heart failure after myocardial infarction (MI). We administered 10 mg/kg/day of A-127722 to rats post-MI for 6 weeks. A hemodynamic study was performed and passive pressure-volume curves obtained. In rats without infarcts, ETA receptor antagonist (n=8; vehicle, n = 5) had no effect. However, in rats with infarcts ETA antagonism (n = 14, MI = 35%; vehicle: n = 19, MI = 32%) reduced systemic arterial and LV systolic (but not end-diastolic) pressures and shifted the pressure-volume relationship to the right. Because LV mass was not changed, the volume-to-mass ratio was increased and was correlated inversely with the ability of the LV to maximally develop pressure. This increase in volume at low distending pressures was also coupled with a tendency (P < 0.06) for reduced scar thickness, suggesting that early initiation of an ETA receptor antagonism increased infarct expansion. The reduction in blood pressure offset the increase in volume such that wall stresses were unchanged, as was LV mass. The early use of ETA receptor antagonism in the rat model of myocardial infarction did not beneficially alter LV remodeling.

Adrenergic mechanisms in human hypertension and in spontaneously hypertensive rats.

Abstract: 1. The role of adrenergic neuronal mechanisms in the development of early hypertension in man and the spontaneously hypertensive rat has been explored. 2. In both, a hyperkinetic circulatory state is associated with reduced parasympathetic and increased adrenergic cardiac influences. 3. Spontaneously hypertensive and normotensive control rats were treated with propranolol from conception until 12 weeks. Although heart rate and output remained reduced, there was no difference in growth or elaboration of pressure with respect to their untreated controls. 4. After another series of spontaneously hypertensive and control rats received cardiac autonomic blockade (atropine and timolol), they sequentially received alpha-adrenergic blockade (phenoxybenzamine), ganglionic blockade (trimethaphan) and smooth-muscle vasodilatation (hydralazine). These studies revealed only a small pressure differential between the two groups before hydralazine and still less thereafter; unlike the control rats, pressure in spontaneously hypertensive rats fell markedly after ganglionic blockade as a result of reduced output, indicating greater adrenergic control mediated through venoconstriction. 5. These findings indicate: increased cardiovascular adrenergic control in young spontaneously hypertensive rats, the hyperkinetic circulation merely reflecting one aspect of increased total cardiovascular input. Structural alterations seem to participate minimally. 6. These experimental observations closely resemble findings in early hypertensive man, and it is suggested that altered total cardiovascular adrenergic input is responsible for the elaboration, development, and maintenance of essential hypertension in man.

Right Ventricular Function, Pulmonary Pressure Estimation, and Clinical Outcomes in Cardiac Resynchronization Therapy

Abstract: Background—Right ventricular function (RVF) is an important determinant of outcome in patients with heart failure, and those with severe RV dysfunction have worse outcome after cardiac resynchronization therapy (CRT). We used data from the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) Trial to determine whether therapy with CRT is influenced by or affects RV function and to define the relationship between RV function and outcomes. Methods and Results—A total of 1820 patients were randomly assigned to CRT plus implantable cardioverter defibrillator or implantable cardioverter defibrillator-only in a 3:2 ratio. We assessed RVF as RV fractional area change by echocardiography at baseline and after 1 year of therapy (n=1511 and 1273, respectively). The median RV fractional area change was 41%, with 10.9% of patients <35% at baseline. Baseline RVF did not modify the treatment effect of CRT on the primary outcome (interaction P=0.19). Randomization to ...

Serum Phosphate: A Novel Cardiovascular Risk Factor Even in Nonrenal Patients Relation between Serum Phosphate Level and Cardiovascular Event Rate in People with Coronary Disease. Circulation 112: 2627-2633, 2005

Abstract: It has been known for decades that hyperphosphatemia is a feature of ESRD that may cause secondary hyperparathyroidism and soft tissue calcification ([1][1]), including vascular calcification ([2][2]). The latter comprises mainly calcification of intimal plaques ([3][3]) and of the media ([4][4],[5

The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report.

Abstract: "The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure" provides a new guideline for hypertension prevention and management. The following are the key messages(1) In persons older than 50 years, systolic blood pressure (BP) of more than 140 mm Hg is a much more important cardiovascular disease (CVD) risk factor than diastolic BP; (2) The risk of CVD, beginning at 115/75 mm Hg, doubles with each increment of 20/10 mm Hg; individuals who are normotensive at 55 years of age have a 90% lifetime risk for developing hypertension; (3) Individuals with a systolic BP of 120 to 139 mm Hg or a diastolic BP of 80 to 89 mm Hg should be considered as prehypertensive and require health-promoting lifestyle modifications to prevent CVD; (4) Thiazide-type diuretics should be used in drug treatment for most patients with uncomplicated hypertension, either alone or combined with drugs from other classes. Certain high-risk conditions are compelling indications for the initial use of other antihypertensive drug classes (angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, β-blockers, calcium channel blockers); (5) Most patients with hypertension will require 2 or more antihypertensive medications to achieve goal BP (<140/90 mm Hg, or <130/80 mm Hg for patients with diabetes or chronic kidney disease); (6) If BP is more than 20/10 mm Hg above goal BP, consideration should be given to initiating therapy with 2 agents, 1 of which usually should be a thiazide-type diuretic; and (7) The most effective therapy prescribed by the most careful clinician will control hypertension only if patients are motivated. Motivation improves when patients have positive experiences with and trust in the clinician. Empathy builds trust and is a potent motivator. Finally, in presenting these guidelines, the committee recognizes that the responsible physician's judgment remains paramount.

Cochrane Handbook for Systematic Reviews of Interventions

Abstract: The Cochrane Handbook for Systematic Reviews of Interventions is the official document that describes in detail the process of preparing and maintaining Cochrane systematic reviews on the effects of healthcare interventions.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

A New Equation to Estimate Glomerular Filtration Rate

Abstract: The Modification of Diet in Renal Disease (MDRD) Study equation underestimates glomerular filtration rate (GFR) in patients with mild kidney disease. Levey and associates therefore developed and va...

Lifetime Prevalence and Age-of-Onset Distributions of DSM-IV Disorders in the National Comorbidity Survey Replication

Abstract: Context Little is known about lifetime prevalence or age of onset of DSM-IV disorders. Objective To estimate lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the recently completed National Comorbidity Survey Replication. Design and Setting Nationally representative face-to-face household survey conducted between February 2001 and April 2003 using the fully structured World Health Organization World Mental Health Survey version of the Composite International Diagnostic Interview. Participants Nine thousand two hundred eighty-two English-speaking respondents aged 18 years and older. Main Outcome Measures Lifetime DSM-IV anxiety, mood, impulse-control, and substance use disorders. Results Lifetime prevalence estimates are as follows: anxiety disorders, 28.8%; mood disorders, 20.8%; impulse-control disorders, 24.8%; substance use disorders, 14.6%; any disorder, 46.4%. Median age of onset is much earlier for anxiety (11 years) and impulse-control (11 years) disorders than for substance use (20 years) and mood (30 years) disorders. Half of all lifetime cases start by age 14 years and three fourths by age 24 years. Later onsets are mostly of comorbid conditions, with estimated lifetime risk of any disorder at age 75 years (50.8%) only slightly higher than observed lifetime prevalence (46.4%). Lifetime prevalence estimates are higher in recent cohorts than in earlier cohorts and have fairly stable intercohort differences across the life course that vary in substantively plausible ways among sociodemographic subgroups. Conclusions About half of Americans will meet the criteria for a DSM-IV disorder sometime in their life, with first onset usually in childhood or adolescence. Interventions aimed at prevention or early treatment need to focus on youth.